Research projects

My research activity is focused on theoretical modeling of materials at the atomic scale. I am particularly interested in using first-principles methods such as Density Functional Theory (DFT) to understand catalytic processes related to energy conversion and storage as well as processes relevant to the chemical industry. Here are some recent research projects I workin on.


Water splitting for energy storage 

Through photosynthesis plants are able to convert and store the energy of sunlight by oxidizing water to molecular oxygen, releasing protons and electrons that are used to reduce CO2 to carbohydrates. However, they do so with very low efficiency. Exploiting this strategy for solar energy storage on an industrial scale would requires efficient and inexpensive catalysts to carry out these redox processes. We focus on the anodic reaction, water oxidation, and study the mechanism of water oxidation catalyzed by some of the most efficient catalysts synthesized to date. The goal is to obtain a detailed atomistic understanding of the processes, to help designing optimal catalysts.


Ethylene epoxidation

Ethylene oxide (EO), obtained industrially through partial oxidation of ethylene on silver catalysts, is an important chemical used as an intermediate in the production of glycols and plastics. We study the mechanism of reaction promoted by Ag and Ag-Cu alloys by means of DFT calculations. We have shown that the Ag-Cu alloy forms a thin copper-oxide-like layer on top of Ag, which explains the observed improved selectivity of the alloy w.r.t. pure silver. We are currently investigating the role of sub-surface oxigen of the selectivity torwards the formation of EO.



Lattice-gas Hamiltonian + Kinetic Monte Carlo description of CO oxidation

CO oxidation is one of the most studied heterogeneous catalytic processes, due to its scientific and technological relevance. On single crystal surfaces such as Pt(111) and Pd(111), the lateral interactions among adsorbate play a large role, modifying the reaction mechanism as temperature and pressure are changed. On Pd(111), in particular, the oxygen islands undergo a structural phase transition that modify the reaction site, the reaction order and the activation barriers. We use a DFT-derived Lattice-gas Hamiltonian model of the energetics of the system, combined with kinetic Monte Carlo modeling of the kinetics of the catalytic processes, with the goal of understanding the origin of the different catalytic behavior of the various surface structures.  


QM/MM in Quantum ESPRESSO

We are developing an interface between Quantum-Espresso and LAMMPS to carry out QM/MM simulations. In this hybrid approach a portion of the system (QM) will be treated at the DFT level (Quantum-Espresso), while the remaining part of the system will be described using empirical force fields (LAMMPS).